1. Field of Invention
This invention relates to agricultural planting equipment and, more particularly, to a metering device drive motor for dispensing seeds and/or fertilizer.
2. Description of Related Art
As is well-known, a farmer engaged in mechanized planting of seeds utilizes a planting machine pulled behind a tractor. One form of planting machine commonly in use includes at least one rotating drum which holds the supply of seeds to be planted and has means for delivering the seeds to one or more chutes which conduct the seeds to the desired planting rows on the ground at various depths and spacings. The seeds are singulated and metered by a seed metering disc with pockets, holes or combinations thereof, and using either a vacuum or positive air pressure. Seed meters require a drive source to rotate the seed disc in order to singulate seed for planting.
Current technology typically uses a ground drive assembly that drives all meters simultaneously through a chain drive mechanism connected to a drive wheel that defines the rate of speed of forward motion of the planter. This mechanical drive assembly requires a multitude of rotating shaves, bearings, support brackets, sprockets, chains and idlers. This approach requires the implement to be stopped while one or more chains are moved and positioned about various sized sprockets or gears.
Other agricultural seed metering systems have been developed which allow the seed metering rate to be adjusted on the go while crossing a field. Such systems typically omit mechanical ground drive assemblies and instead rely on electronics to control hydraulic systems for accurate metering. To adjust the metering rate, the electronics control the hydraulic system to adjust the hydraulic oil flow sent to the hydraulic motor to adjust the rate at which the rotatable metering member is rotated.
Although such systems enable the metering rate to be adjusted on the go, such electronic metering systems are extremely expensive to implement and are difficult to diagnose and repair when damaged. Moreover, as compared to ground driven mechanical metering systems, such electronic metering systems require an additional hydraulic circuit to drive the hydraulic motors connected to the rotatable metering members. This additional hydraulic circuit increases hydraulic requirements of the work vehicle or tractor and when connected to open center hydraulic systems, can cause overheating problems. This drive assembly also requires a multitude of rotating shaves, bearings, support brackets, sprockets, chains and idlers.
Thus, there is a continuing need for an agricultural seed metering system that allows the operator to vary the speed of each metering unit individually, is adjustable on the move, and reduces the parts and space required for rotational power requirements.